Sound-reproducing apparatus



Dec. 28 1926. 1,612,086

A. P. YOUNG SOUND REPRODUCING APPARATUS Filed Jan. 20. 1925 Inventor:

Arthur P Young,

His Attov heg.

Patented Dec. 28, 1926.

* UNITED ,STATESVA'FPATENT OFFICE.

ARTHUR PRIMROSE YOUNG, OF KENILWORTH. ENGLAND, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CQRPORATION OF NEW YORK.

sounn-nnrnonucme nrrannrus.

Application filed January 20, 1925. Serial No.

My present invention broadly consists in the provision of apole-piece formed from a strip of suitable material which is bent into three planes, each approximately at right angles to one another. In making such a pole-piece from "a flat strip, the strip may formed into a. substantially L-shapedmember by removing one of its corners (for instance, by punching out a portionincluding one of the corners) and the arms of the L-shaped member, or a portion of either arm may then be bent each substantially through a right an 1e and on to the opposite sides of the mid le portion of the L-shaped member. Two. similar pole-pieces may be -arranged with similar projecting portions ad-f jacent to one another for carrying coils, the other projecting portions, respectively, lying against the poles of one or more permanent or electro-magnets. j

My invention will best be understood by reference to the following description taken in connection with the accompanying drawing in which Figs. 1 to 4 illustrate'the vari-- ous steps which may' be taken in the construction ofpole pieces in accordance with my invention; and Fig. 5 is a top plan view of the telephone receiver with "the diaphragm, cover and coils removed.

, In the construction of pole pieces in accordance with my invention two similar rectangular portions 11, as indicated in- Fig. 1,

may be punched out from the corners at the end of one of the sides'of a substantially rectangular strip ofsuitable material, such as soft iron or mild rolled steeLr A third mg portion 13 of the strip remaimng be tween the two cut-away rectangles 11. The

two projecting portions 18 thus formed may then be bent at right angles to-the original 3,691, and in Grcat Britain February 20, 1924.

plane of the strip. It should be noted that the operation so far described can be accomplished at each stroke of a suitably designed power press, and Fig. 1 shows the shape at this stage. After this, the endsl l of the stripmaybe bent downwards at right angles to the strip and on the other side from 'which the middle portions 13 project, this being shown in Fig. 21 v Next the strip may be'divided into two similar portions, forming thereby two similar pole-pieces. These pole-pieces may then be arranged with their similar projecting portions 14 adjacent to and spaced from one .another and they may be clamped in this position by means of a member 1-5-01? nonmagnetic'material, such as brass, which may be riveted thereto, asis shown in Fig. 3 or 4.. This iin ert may then be placed in a steel or any material having strong magnetic properties, the magnet being retained in position by means of a set screw 19 or other clamping means. This shown in Fig. 5. Alternatively, before the insert is placed in the moulding, the permanent magnet, which may be a bar arranged alongside of. or a curved magnet with its ends passing under the middle ortion of each pole-piece, may be clamped in position with its poles adjacent the projecting portions '13 on the pole-pieces and-the whole then. subjected tothe moulding o eration, previously described, the groove 1% being, of course omitted.

According to another method of construction the pole-pieces] before the strip has been'divided into two similarpoIe pieces, two or more strips may be placed in line and in a similar sense (for 1nstance,' with the ends 14 of each strip all projecting downwards),'-each-'strip being spaced fromits adjacent strip or strips a predeterminedarrangement is Y upon and riv'etedto each .pair of adjacent strips so as to. hold them firmly in spaced llU i are relation to one another. Or a continuous member of non-magnetic material may he placed along and riveted to the original strips. It now remains to divide each of the original strips, in half, which leaves a number of pairs of pole pieces suitably spaced and fixed with respect to one another, the outside ends of the two outside strips being Waste metal. Each pair of polepieces may then be attached to a magnet and or placed in a mould together witha composite insulating material which may be moulded to embed a portion of the magnetic structure.

Finally, suitably Wound coils, which. for convenience of illustration me not shown on the drawing, may be placed upon and secured to the poles 14 and their ends may be connected to terminals 20 adapted to screw into the insulating material and to be attached to the main leads.

i What I claim as neiv'and desire to secure by Letters'Patent of the United States is l. A pole piece for an electro-magnetic sound reproducing device consisting of a 'strip of magnetic material havingthree portions extending in three planes which are ap proximately at-right angles to each other, two of said portions extending in opposite directions from the third portion, one of the oppositely extending portions providing .a core on which a winding may be supported and the other an anchoring means for the pole piece.

2. A telephone receiver which comprises relapse tions extending in three plane which are approximately at right angles to each other, each of said pole pieces having one portion embedded in amass of insulating material.

and another portion projecting from the mass of insulating material, and a permanent magnet having its poles adjacent the embedded portions of the pole pieces.

4. A telephone receiver which comprises a pair of pole pieces each consisting of a strip of magnetic material having three portions extending in three planes which are approximately at right angles to each other, each of said pole pieces having one portion embedded in a mass of insulating material and another portion projecting from the mass of insulating material, a slot-in said mass of insulating material, and a permanent mag, net located in said slot and having its polesadjacent the embedded portions of the pole pieces.

In witness whereof, l have hereunto set my hand this 31st day of December 1924.

ARTHUR PRIMROSE YOUNG. 

